Mika Brzezinski — co-host of MSNBC's "Morning Joe" — appeared to suggest Friday that President Donald Trump isn't the father of Barron Trump.

Although Brzezinski did seem more confident that Barron's mother is first lady Melania Trump.

What happened?

Amid a chat about former Vice President Joe Biden's performance during Thursday night's Democratic presidential debate, "Morning Joe" co-host Joe Scarborough said, "We're going to have a new segment on 'Morning Joe,' and it's going to be called 'Adventures in Syntax.'"

He then pointed out Trump's apparent gaffe when "talking about Melania's son" Wednesday at the White House regarding the dangers of vaping. Trump said, "She's got a son — together — that is a, a beautiful young man."

Apparently, Brzezinski couldn't resist.

"Maybe it is Melania's son," she quipped.

"Well, it is Melania's son," Scarborough answered.

"Well, that's what he was saying ... just her son. That's not — that's just what he said," Brzezinski continued, as things grew more uncomfortable.

Scarborough wasn't going there: "Well, let me get back to Biden because I don't ... know exactly what you're saying."

Brzezinski helped out her hubby: "Well, it seems like he didn't remember Barron's name or…"